college algebra--please

posted by .

I am not understanding this question and I have read the chapter many times. Please help.

given the function of f(x)=4x-8

a. find the the rate of change between the stated values for x:5 to 7

b. find the equation of a secant line containing the given points (5,f(5)), and (7,f(7))

Like I said I have no clue. Can you please show me how you got the answer please?

  • college algebra--please -

    rate of change is (change in y)/(change in x)

    f(5) = 12
    f(7) = 20

    y changes from 12 to 20 as x changes from 5 to 7:

    rate of change is thus (20-12)/(7-5) = 8/2 = 4

    Note that the rate of change is the same as the slope of the line f(x)=4x-8

    The secant line is thus the line from (5,12) to (7,20). Or, it is the line from (5,12) with a slope of 4. Either way, you get

    (y-12) = 4(x-5)
    y = 4x -8

    This is not surprising, since the secant joining any two points on a line is just a section of the same line.

    It strikes me as odd that such a problem is posed. Could it be that the function is

    f(x) = 4^x-8. Probably not, as the values of f(x) would be quite large.

    Oh well, if the function is wrong, just use the method above to find the secant.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Calculus Please Help

    Given the numerical values shown for the function f(x), find approximate values for the derivative of f(x) at each of the x-values given. x= 0 1 2 3 4 5 6 7 8 f(x)= 13 15 16 17 17 14 11 9 7 f'(x)= 2 1 1 1 0 -3 -3 -2 -2 What seems to …
  2. college algebra

    A function is given. Determine the average rate of change of the function between the given values of the variable. f(t) = 6/t ; t = a, t = a + h
  3. college algebra

    A function is given. Determine the average rate of change of the function between the given values of the variable. f(x) = 6 − x2; x = 1, x = 1 + h
  4. calculus

    Given the function f(x) = 3x - 9 a. Find the rate of change between the two stated values for x: 7 to 8 b. Find the equation of a secant line containing the given points: (7, f(7)) and (8, f(8))
  5. math

    can someone please help me with this question. Given the funtion f(x)= 3x-9 a. find the rate of change between the two stated values for x: 7 to 8 b. find the equation of a secant line containing the given points: (7,f(7)) and (8,f(8)) …
  6. pre-calculas

    can someone please help me with this question?
  7. college algebra

    given the functionf(x)=x^3+3x find the rateof change between the two stated values for x:1 to 2 find the equation of a secant line containig the given points (1,f(1))and (2,f(2))
  8. college algebra

    given function f(X)=X^3+3x findthe rate of change between the two stated values for x:1 to 2 find the equation of a secant line (1,f(1)and(2,f(2))
  9. college algebra

    Given the function f(x) = x^3+ 3x Find the rate of change between the two stated values for x: 1 to 2 Find the equation of a secant line containing the given points: (1, f(1)) and (2, f(2))
  10. college algebra

    given the function fx=x^3+x a) find the rate of change between the two stated values for x: 1 to 2 B)find the equation of a secant line containing the given points (1,f(1))and (2,f(2)

More Similar Questions